{"product_id":"sierra-18-1211-two-piece-rear-main-seal-replaces-mercruiser-26-49947-omc-473424-fits-gm-2-5l-3-0l-inline-4-3l-v6-5-0l-5-7l-v8-marine-engines","title":"Sierra 18-1211 Two-Piece Rear Main Seal for 3.8L Marine Engines","description":"\u003cp\u003eThe Sierra 18-1211 is a two-piece rear main crankshaft seal designed to seal the rear of the crankshaft where it exits the engine block on applicable marine engines. It is built to meet or exceed the fit, form, and function of the original equipment seal it replaces, giving boat owners a dependable option when rebuilding an engine or addressing a rear main oil leak. The two-piece construction allows the seal to be installed around the crankshaft without full engine disassembly in many rebuild situations, which is a common design advantage over full-circle, one-piece seals that require the crankshaft to be pulled.\u003c\/p\u003e\u003cp\u003eThis seal is used on 3.8L marine engines, where it is paired with a separate oil pan gasket during a rear main seal service. It also cross-references to a wide range of OMC, Evinrude\/Johnson, Mercruiser, GLM, and Mallory rear main seal part numbers, making it a straightforward replacement for engines originally fitted with those components. As with all rear main seal jobs, a proper installation is important to prevent oil leaks at the rear of the crankcase, and the corresponding rear main crankshaft seal housing or block surface should be clean and free of damage before installation.\u003c\/p\u003e\u003ch3\u003eSpecifications\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eBrand:\u003c\/strong\u003e Sierra\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eManufacturer Part Number:\u003c\/strong\u003e 18-1211\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePart Type:\u003c\/strong\u003e Rear Main Seal\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDesign:\u003c\/strong\u003e Two-Piece\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eAuto Part Position:\u003c\/strong\u003e Rear\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eIncluded Components:\u003c\/strong\u003e Rear Main Seal\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eQuantity:\u003c\/strong\u003e 1\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWeight:\u003c\/strong\u003e 0.07 pounds\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eFitment\u003c\/h3\u003e\u003cul\u003e\u003cli\u003e3.8L marine engine models\u003c\/li\u003e\u003c\/ul\u003e\u003ch3\u003eReplaces (OEM)\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003eGLM 85490\u003c\/li\u003e\n\u003cli\u003eEvinrude\/Johnson 473423\u003c\/li\u003e\n\u003cli\u003eMallory 9-61620\u003c\/li\u003e\n\u003cli\u003eMercruiser FI5110041\u003c\/li\u003e\n\u003cli\u003eMercruiser FI5110027\u003c\/li\u003e\n\u003cli\u003eMercruiser FI5110026\u003c\/li\u003e\n\u003cli\u003eMercruiser 26-49947\u003c\/li\u003e\n\u003cli\u003eMercruiser 26-58203\u003c\/li\u003e\n\u003cli\u003eMercruiser 26-814622\u003c\/li\u003e\n\u003cli\u003eOMC 473424\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eFrequently Asked Questions\u003c\/h3\u003e\u003cp\u003e\u003cstrong\u003eWhat engines does the Sierra 18-1211 rear main seal fit?\u003c\/strong\u003e The Sierra 18-1211 is designed for 3.8L marine engine models.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs the 18-1211 a one-piece or two-piece seal?\u003c\/strong\u003e It is a two-piece rear main seal, which allows installation around the crankshaft without requiring full engine disassembly in many rebuild scenarios.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat OEM part numbers does the Sierra 18-1211 replace?\u003c\/strong\u003e This seal cross-references to GLM 85490, Evinrude\/Johnson 473423, Mallory 9-61620, Mercruiser FI5110041, FI5110027, FI5110026, 26-49947, 26-58203, and 26-814622, and OMC 473424.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eDo I need any other gaskets when installing the 18-1211?\u003c\/strong\u003e On 3.8L models, the 18-1211 rear crank seal is used along with a separate oil pan gasket, part number 18-0362.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow much does the Sierra 18-1211 rear main seal weigh?\u003c\/strong\u003e The Sierra 18-1211 weighs 0.07 pounds.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs the Sierra 18-1211 a genuine Sierra part or aftermarket equivalent?\u003c\/strong\u003e The 18-1211 is a Sierra-brand rear main seal manufactured to meet or exceed the original equipment part it replaces.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat comes included with part number 18-1211?\u003c\/strong\u003e The package includes one rear main seal, sold as a single unit (quantity 1).\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhere is this seal located on the engine?\u003c\/strong\u003e The Sierra 18-1211 is installed at the rear position of the crankshaft, sealing the point where the crankshaft exits the rear of the engine block.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eCan the Sierra 18-1211 replace a Mercruiser rear main seal?\u003c\/strong\u003e Yes, the 18-1211 cross-references to several Mercruiser part numbers, including FI5110041, FI5110027, FI5110026, 26-49947, 26-58203, and 26-814622.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eDoes the Sierra 18-1211 fit OMC or Evinrude\/Johnson engines?\u003c\/strong\u003e It cross-references to OMC 473424 and Evinrude\/Johnson 473423, so it fits engines that originally used those rear main seals.\u003c\/p\u003e","brand":"Sierra","offers":[{"title":"Default Title","offer_id":48988087025883,"sku":"SIE-18-1211","price":60.39,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0839\/7586\/4539\/files\/SIE-18-1211_lg__43814.1722509909.500.750.jpg?v=1785188418","url":"https:\/\/www.goodvibesmarina.com\/products\/sierra-18-1211-two-piece-rear-main-seal-replaces-mercruiser-26-49947-omc-473424-fits-gm-2-5l-3-0l-inline-4-3l-v6-5-0l-5-7l-v8-marine-engines","provider":"Good Vibes Marina","version":"1.0","type":"link"}